Field of the Invention
The invention relates to a defect inspection methodology; more particular, the invention relates to a method and a system for detecting defects of a wafer by water sort (WS).
Description of Related Art
In the semiconductor process, all integrated circuits on the wafer have to be tested to increase the product yield. For example, the wafer testing is performed by a piece of test equipment called a wafer prober. The process of wafer testing can be referred to in several ways: Wafer Sort (WS), Wafer Final Test (WFT), Electronic Die Sort (EDS) and Circuit Probe (CP) are probably the most common.
The WS repair function makes most of failure sites being repaired, and then there is no exactly site to match. In addition, WS reports only shows Die base (by die, not by sites), so it is hard to match defects. Furthermore, WS results are hard to match real defects unless the wafer is worse and low yield, and thus it is also hard to calculate the killing ratio vs. defect by layers.